–
+
Distant changes alter curvature cancellation
¥damage: remove bending energy from core region
–central force F decreases
–curvature cancellation is incomplete
–\cancellation † uniform elasticity
Thus: curvature cancellation
results from global constraints.
deform:
circular rim¨elliptical rim
Mean curvature varies along the rim
Becomes negative at minor axis
r
0
Jin Wang, TW 2009